1. Field of the Invention
The present invention relates to portable saws having a device that prevent chips generated by a cutting operation from scattering to the surrounding area.
2. Description of the Related Art
A known portable saw having a device for preventing cutting chips from scattering is taught in Japanese Utility Model Publication No. 6-47683. For explanation purposes, FIG. 2 from this Japanese Utility Model Publication has been reproduced as FIG. 8 in this application. As shown in FIG. 8, the known portable saw consists of a bifurcated chip cover 52 that has a pair of lateral walls 52a and a front wall 52b so as to cover both lateral sides and the front side of a cutting chip exhaust area, which area is normally defined as a position adjacent to a base 53 on the front side (right side as viewed in FIG. 8) of a saw blade 51. The base 53 is adapted to be placed on a workpiece and the saw blade 51 can be moved to partly extend through the base 53 to cut the workpiece. The chip cover 52 may prevent the cutting chips of the workpiece from being exhausted either forwardly or laterally. Instead, the cutting chips are intended to be swept upwardly in the rotational direction of the saw blade 52 (as indicated by an arrow in FIG. 8) so as to be collected in a chip collector (not shown).
The chip cover 52 is mounted so as to pivot vertically on a bracket 53a by means of a pin 54. The bracket 53a is fixed to the upper surface of the base 53. A torsion spring 55 serves to normally bias the chip cover 52 to contact the upper surface of the base 53. The saw blade 51 is rotatably mounted on a saw unit 56 that also is mounted so as to vertically pivot around the bracket 53a by means of a pin 57. A motor (not shown) drives the saw blade 51.
As the saw unit 56 pivots upward relative to the base 53, the blade profile below is reduced, so that the cutting depth of the saw blade 51 into the workpiece is reduced. Because the chip cover 52 is biased by the torsion spring 55 to contact the base 53, both lateral sides of the cutting chip exhaust area are covered by the lateral walls 52a of the slide cover 52.
However, because the saw blade 51 separates from the front wall 52b of the chip cover 52 as the saw unit 56 pivots upward, the space between the saw blade 51 and the front wall 52b increases. In other words, the front wall 52b moves away from the cutting chip exhaust area. As a result, the known slide cover may not effectively prevent the cutting chips from scattering to the surrounding area.